CN1408196A - Linear accelerator - Google Patents
Linear accelerator Download PDFInfo
- Publication number
- CN1408196A CN1408196A CN00811028A CN00811028A CN1408196A CN 1408196 A CN1408196 A CN 1408196A CN 00811028 A CN00811028 A CN 00811028A CN 00811028 A CN00811028 A CN 00811028A CN 1408196 A CN1408196 A CN 1408196A
- Authority
- CN
- China
- Prior art keywords
- accelerator
- ratio
- electric field
- cells
- coupling unit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
- H05H9/00—Linear accelerators
- H05H9/04—Standing-wave linear accelerators
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
- H05H7/00—Details of devices of the types covered by groups H05H9/00, H05H11/00, H05H13/00
- H05H7/14—Vacuum chambers
- H05H7/18—Cavities; Resonators
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Radiation-Therapy Devices (AREA)
- Particle Accelerators (AREA)
Abstract
An accelerator comprises a plurality of accelerating cells arranged to convey a beam, adjacent cells being linked by a coupling cell, the coupling cells being arranged to dictate the ratio of electric field in the respective adjacent accelerating cells, at least one coupling cell being switchable between a positive ratio and a negative ratio. Such an accelerator in effect inserts a phase change into the E field by imposing a negative ratio, meaning that the beam will meet a reversed electric field in subsequent cells and will in fact be decelerated. As a result, the beam can be developed and bunched in early cells while accelerating to and/or at relativistic energies, and then bled of energy in later cells to bring the beam energy down to (say) between 100 and 300 KeV. Energies of this magnitude are comparable to diagnostic X-rays, where much higher contrast of bony structures exists. Hence the accelerator can be used to take kilovoltage portal images. A suitable structure for the switchable coupling cell comprises a cavity containing a conductive element rotatable about an axis transverse to the beam axis, as for example set out in our earlier application PCT/GB99/00187. The application also relates to the use of such an accelerator and an operating method for such an accelerator.
Description
Invention field
The present invention relates to a kind of linear accelerator.
Background technology
Use radium in the treatment of cancer and during other disease, powerful suitable radiation beam is drawn towards patient's stymied zone making.Described radiation beam is easy to kill the cell of the work in its path, thereby it is used for kill cancer cell, therefore, is starved of and guarantees that radiation beam correctly aims at.Can not aim at the healthy cell that just may cause not destroying patient with needing.The situation of using some kinds of method inspections to aim at, a kind of important inspection is to use so-called " inlet image " (portal image).This is a kind of image that forms by placement photographic plate or electronic imaging base plate below patient during short irradiation.Radiation beam is stayed image by patient's internal and tissue decay on base plate.Then, before finishing treatment or after the radiation doses, can check, correctly aim at so that guarantee.
Yet, explain that the inlet image is extremely difficult.The energy that reaches the required radiation beam of useful result of treatment is more much bigger than the energy that is used for medical imaging.Under these higher energy, the relative attenuation between bone and the institutional framework has less ratio, and this makes the inlet image have poor contrast.Thereby be difficult to distinguish structure in the patient body.
Some existing radiotherapy units comprise second radioactive source, and it is applicable to and produces low-energy radiation beam, is used for producing the inlet image.Described second radioactive source is placed in the next door of main accelerator and parallel with it usually, perhaps install, make whole device rotate, thereby second radioactive source is aimed at so that form the inlet image around patient with such angle, then, handle assembly turns to the original place and treats.These two kinds are arranged in and have difficulties aspect the enough adjustment that guarantee between the main accelerator and second radioactive source.
Can not reduce the energy of main (treatment) accelerator so far simply, because this must be in relativistic mode (relativistic mode) operation down, so that keep the quality of radiation beam.If last radiation beam energy is too low, then radiation beam will become at the early part of accelerator nonrelativistic, the operation that can not be satisfied with.
The present invention's general introduction
Therefore, the invention provides a kind of accelerator, it comprises a plurality of accelerator modules that are provided to carry radiation beam, adjacent accelerator module is linked by coupling unit, described coupling unit is provided to determine the ratio of the electric field in each adjacent accelerator module, and wherein at least one coupling unit can switch between direct ratio and negative ratio.
Sort accelerator is specially adapted to treatment as the part of radiotherapy equipment, because negative than phase change is inserted in the E electric field effectively by adding, this means that radiation beam will run into the reversed electric field in consecutive elements, and in fact will be decelerated.As a result, can produce radiation beam in the unit in early days and, under the theory of relativity energy, quicken simultaneously by pack, and then in later unit energy emitted, thereby make the radiation beam energy decreases for example 100 and 300KeV between.The output energy that even now is low, radiation beam are relativistic on the equal length of accelerator basically, as previously mentioned.Da Xiao energy can be compared with diagnosis X radial like this, wherein has the much higher contrast of bone structure.Thereby sort accelerator can be used for taking the inlet image of kilovolt.
Preferably, this switchable coupling unit comprises that one contains the cavity of conducting element, and described conducting element can be around the rotational perpendicular to the bundle axis.This is preferred, and as described in our earlier application PCT/GB99/00187, please specially with reference to this patent, and the content of this patent is classified reference as at this.For seeking protection in the feature of the application's proposition and the combination of features that in described patent, proposes.
The application relates to the use of accelerator equally, wherein be provided with a plurality of accelerator modules and be used to carry radiation beam, and adjacent accelerator module is linked by coupling unit, described coupling unit is provided to determine the ratio of the electric field in each adjacent accelerator module, and wherein at least one coupling unit switches between direct ratio and negative ratio.
In addition, the application relates to a kind of method of operation of accelerator, in described accelerator, be provided with a plurality of accelerator modules to carry radiation beam, and adjacent accelerator module is linked by coupling unit, described coupling unit is provided to determine the ratio of the electric field in each adjacent accelerator module, and wherein at least one coupling unit switches between direct ratio and negative ratio.
The accompanying drawing summary
Below with way of example with reference to the description of drawings embodiments of the invention, wherein:
Fig. 1 is the schematic diagram of conventional linear accelerator;
Fig. 2 is illustrated in electric field required in the accelerator of Fig. 1;
Fig. 3 represent by the electronics that is accelerated " observation " to typical electric field;
Fig. 4 represents according to linear accelerator of the present invention;
Fig. 5 is illustrated in the change of unit 108 and each coupling coefficient between two adjacent coupling units of Fig. 4, and expression is when conducting element (blade) rotates, the quantitative change of these coupling coefficients;
Fig. 5 a, 5b proposes the explanation to Fig. 5;
Fig. 6 represents by the electric field of seeing for the electronics of the accelerator of the pivo table member of the E-electric field setting that reduces that has that is used for Fig. 4;
Fig. 7 represents to have the similar electric field of the pivo table member that is provided with for the E-electric field that raises; And
Fig. 8 represents to have another electric field of the pivo table member that is provided with for reverse E-electric field.
The detailed description of embodiment
Referring to Fig. 1, conventional accelerator 100 has a series of accelerator module, and for example 102.They are configured to a linear array, and are communicated with by the hole on each accelerator module center line 104.The electron beam that quickens passes through each accelerator module along described path.Coupling unit for example 106 is set between the adjacent accelerator module, and the coupling of rf degree is provided between accelerator module.Described coupling is regulated the rf standing wave of being set up by the external device (ED) (not shown) in accelerator.
In general, for each accelerator module of any kind, begin to be numbered continuously from first accelerator module.Thereby first coupling unit between first and second accelerator modules is unit 2.Then, second accelerator module is unit 3.This as shown in Figure 1, and obtain having odd-numbered accelerator module and have the coupling unit of even-numbered.
Fig. 2 is illustrated in the required rf figure in the unit.Diagrammatic representation shown in should be kept in mind that is at sometime standing wave, thereby vibrates between maximum shown in Figure 2 and reversed electric field at the E electric field of the reality of an ad-hoc location.In theory, described electric field is positive in unit 1, is 0 in the unit 2, bear in the unit 3, and be 0 in the unit 4.Then, it repeats this figure, is 0 in coupling unit, and has the polarity of alternation in accelerator module in succession.The size quilt of accelerator and the frequency dependence ground of rf standing wave determines, makes when the electronics that quickens during from a unit to another unit motion, and for example from the unit 23 when moving to unit 25, described standing wave will be finished a half period.As a result, when electronics arrived unit 25, the value of the E electric field in unit 25 and the electronics value in unit 23 time was opposite.Thereby, in each accelerator module, it seems that the E electric field is positive, thereby in the traveling process of electronics, electronics will obtain energy from the E electric field always in each accelerator module with regard to electronics.
In a back accelerator module, the energy of electronics gives its motion relativistic.Thereby when it obtained energy, it is constant and irrelevant with the kinetic energy of its increase that its speed keeps substantially.This makes the phase relation between the rf standing wave and the electronics of advancing be maintained fixed.Therefore, importantly make radiation beam keep relativistic because otherwise electronics will lose synchronously with the rf standing wave.Therefore, can not be by reducing the output energy that acceleration (being rf power) reduces radiation beam, though because radiation beam should be relativistic when output in theory, it is nonrelativistic on the fundamental length of accelerator, so radiation beam will lose Phase synchronization.
Fig. 3 is illustrated in electronics by the observed curve of real E electric field basically of described electronics during the accelerator.If as can be seen, have in individual point corresponding to the center of quickening cavity, wherein the E electric field is very strong and be positive.Electric field is very little between these zones, and can ignore.In the unit, electric field is near required electric field.
Fig. 4 represents according to linear accelerator of the present invention.Unit 10 has been replaced by a variable coupling unit 108, and unit 108 comprises a columniform basically cavity 110, and its axis perpendicular to accelerator is arranged, and wherein places a rotatable blade 112.This has illustrated that in our earlier application PCT/GB99/00187 the reader can be with reference to described patent.Described in the patent application, this structure makes it possible to obtain the wide scope of coupling coefficient ratio as described.But, find out further now that this structure in fact can produce a negative coupling coefficient ratio, as shown in Figure 5.Fig. 5 represents coupling coefficient and the ratio between them when 360 ° of blade rotation.As can be seen from the figure, in certain angular range of blade, two coupling coefficients have identical symbol, thereby the ratio between them is positive, but in other blade angle scope, coupling coefficient has different symbols, thereby described ratio is born.
Exactly because this structure can generation or the coupling coefficient of same-sign or contrary sign, make two parts of linear accelerator or both that the acceleration of particle can both be provided, perhaps wherein a part provides acceleration, and while another part provides the deceleration of particle.
In some zones, described ratio is very big really, thereby accelerator may be very unstable in these zones.But, in other zone, for example according to shown in ratio between 30 ° and 180 °, described ratio can one medium on the occasion of and a medium negative value between change smoothly.
Fig. 5 a, 5b illustrate how this produces.In cavity, the orientation of whole electromagnetic field EM figure is by the determining positions of blade 112, because the power line (114) of (for example) E-electric field must run into vertical conductive surface.But, RF between accelerator module and coupling unit coupling mainly is a magnetic, is to enter paper or come out the axis of described H-electric field by arrow end (* and) expression from paper according to described.
Thereby, when the port one 16 of blade 112 at connection accelerator module and coupling unit, (Fig. 5 a), each port will be seen (for example two *) H-electric field of an identical polar, thereby produce positive coupling coefficient ratio and electron acceleration at the upstream and downstream of coupling unit in the time of between 118.In general, these accelerating field strengths according to the accurate angle setting of blade difference.
When blade 112 strides across port one (Fig. 5 b) at 16,118 o'clock, the polarity of the H-electric field of being seen by port is opposite (for example and *), thereby produces negative coupling coefficient ratio, thereby quickens then to slow down in the downstream at the upstream of coupling unit electronics.
Fig. 6 and Fig. 7 represent respectively to compare accelerator module E electric field effects greater than unit 1 with less than the coupling coefficient of unit 1.In Fig. 6, after unit 10, the electric field that is subjected to by the radiation beam that quickens descends, so radiation beam will obtain less energy, thereby exports energy and diminish.In Fig. 7, after unit 10, the electric field that is subjected to by the radiation beam that quickens increases, so electron beam will obtain more energy, thereby the quantitative change of output energy is big.The equipment of this explanation PCT/GB99/00187 can change the output energy of radiation beam.
Fig. 8 represents the influence of negative coupling coefficient ratio.From the unit 9 to the unit 11 E electric field is opposite, thereby in the rf standing wave, obtain effective phase change.Thereby from the electric field of unit 11 forward, radiation beam is subjected to an E electric field that makes its deceleration, and promptly radiation beam releases energy to the E electric field.Thereby bundle output can have low-down energy really.This feasible inlet image (portal image) that can obtain having enough contrasts.
Past attempts to insert phase change by means of rf electric field and radiation beam are separated in the rf electric field always, and inserts additional half-wavelength path, but produces very big difficulty when reconsolidating (reuniting) rf and radiation beam.This structure has been avoided these difficulties fully.
Certainly very obvious, do not depart from the scope of the present invention, those skilled in the art can make many changes and remodeling to said apparatus.
Claims (7)
1. accelerator, comprise a plurality of accelerator modules, be used to carry radiation beam, and adjacent accelerator module is linked by coupling unit, described coupling unit is provided to determine the ratio of the electric field in each adjacent accelerator module, and wherein at least one coupling unit switches between direct ratio and negative ratio.
2. accelerator as claimed in claim 1, wherein said radiation beam are relativistic on the whole length of accelerator basically.
3. accelerator as claimed in claim 1 or 2, wherein switchable coupling unit comprise that one contains the cavity of conducting element, and described conducting element can be around the rotational perpendicular to the bundle axis.
4. the purposes of an accelerator, in described accelerator, be provided with a plurality of accelerator modules, be used to carry radiation beam, and adjacent accelerator module is linked by coupling unit, described coupling unit is provided to determine the ratio of the electric field in each adjacent accelerator module, and wherein at least one coupling unit switches between direct ratio and negative ratio.
5. the method for operation of an accelerator, in described accelerator, be provided with a plurality of accelerator modules and carry radiation beam, and adjacent accelerator module is linked by coupling unit, described coupling unit is provided to determine the ratio of the electric field in each adjacent accelerator module, and wherein at least one coupling unit switches between direct ratio and negative ratio.
6. as the purposes of any one accelerator in the claim 1 to 3, be used for taking a kilovolt inlet image.
7. accelerator, basically as reference Fig. 4 as described in Fig. 8.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9918787A GB2354876B (en) | 1999-08-10 | 1999-08-10 | Linear accelerator |
| GB9918787.4 | 1999-08-10 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1408196A true CN1408196A (en) | 2003-04-02 |
| CN1190112C CN1190112C (en) | 2005-02-16 |
Family
ID=10858870
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB00811028XA Expired - Lifetime CN1190112C (en) | 1999-08-10 | 2000-08-03 | Linear accelerator |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US6710557B1 (en) |
| EP (1) | EP1203514B1 (en) |
| JP (1) | JP5178978B2 (en) |
| CN (1) | CN1190112C (en) |
| AU (1) | AU6306000A (en) |
| CA (1) | CA2379935C (en) |
| GB (1) | GB2354876B (en) |
| WO (1) | WO2001011928A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103430633A (en) * | 2011-03-14 | 2013-12-04 | 伊利克塔股份有限公司 | Linear accelerator |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100358397C (en) | 2004-02-01 | 2007-12-26 | 绵阳高新区双峰科技开发有限公司 | Phase (energy) switch-standing wave electronic linear accelerator |
| GB2424120B (en) * | 2005-03-12 | 2009-03-25 | Elekta Ab | Linear accelerator |
| US7983380B2 (en) | 2005-04-29 | 2011-07-19 | Varian Medical Systems, Inc. | Radiation systems |
| US20090088625A1 (en) * | 2007-10-01 | 2009-04-02 | Kenneth Oosting | Photonic Based Non-Invasive Surgery System That Includes Automated Cell Control and Eradication Via Pre-Calculated Feed-Forward Control Plus Image Feedback Control For Targeted Energy Delivery |
| US10566169B1 (en) * | 2008-06-30 | 2020-02-18 | Nexgen Semi Holding, Inc. | Method and device for spatial charged particle bunching |
| US20120229024A1 (en) | 2011-03-10 | 2012-09-13 | Elekta Ab (Publ) | Electron source for linear accelerators |
| JP2012209119A (en) * | 2011-03-29 | 2012-10-25 | Mitsubishi Heavy Ind Ltd | X-ray generator and control method thereof |
| GB2513596B (en) | 2013-04-30 | 2020-01-01 | Elekta Ab | Image-guided radiotherapy |
| US10806409B2 (en) | 2016-09-23 | 2020-10-20 | Varian Medical Systems International Ag | Medical systems with patient supports |
| GB2583378A (en) * | 2019-04-26 | 2020-10-28 | Elekta ltd | Waveguide for a linear accelerator and method of operating a linear accelerator |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5857924B2 (en) * | 1976-03-31 | 1983-12-22 | 松下電器産業株式会社 | solid state oscillator |
| US4286192A (en) * | 1979-10-12 | 1981-08-25 | Varian Associates, Inc. | Variable energy standing wave linear accelerator structure |
| US4382208A (en) * | 1980-07-28 | 1983-05-03 | Varian Associates, Inc. | Variable field coupled cavity resonator circuit |
| US4629938A (en) * | 1985-03-29 | 1986-12-16 | Varian Associates, Inc. | Standing wave linear accelerator having non-resonant side cavity |
| JPS61288400A (en) * | 1985-06-14 | 1986-12-18 | 日本電気株式会社 | Stationary linear accelerator |
| JPS6347603U (en) * | 1986-09-16 | 1988-03-31 | ||
| JPH01264200A (en) * | 1988-04-13 | 1989-10-20 | Toshiba Corp | Standing wave linear accelerator |
| US5381072A (en) * | 1992-02-25 | 1995-01-10 | Varian Associates, Inc. | Linear accelerator with improved input cavity structure and including tapered drift tubes |
| JPH1013134A (en) * | 1996-06-24 | 1998-01-16 | Kubota Corp | Receiving antenna for satellite broadcast |
| GB2334139B (en) | 1998-02-05 | 2001-12-19 | Elekta Ab | Linear accelerator |
| JPH11261316A (en) * | 1998-03-10 | 1999-09-24 | Kubota Corp | Receiving antenna system |
-
1999
- 1999-08-10 GB GB9918787A patent/GB2354876B/en not_active Expired - Fee Related
-
2000
- 2000-08-03 CA CA002379935A patent/CA2379935C/en not_active Expired - Lifetime
- 2000-08-03 JP JP2001515661A patent/JP5178978B2/en not_active Expired - Lifetime
- 2000-08-03 EP EP00949794.2A patent/EP1203514B1/en not_active Expired - Lifetime
- 2000-08-03 US US10/049,352 patent/US6710557B1/en not_active Expired - Lifetime
- 2000-08-03 WO PCT/GB2000/003004 patent/WO2001011928A1/en active Application Filing
- 2000-08-03 AU AU63060/00A patent/AU6306000A/en not_active Abandoned
- 2000-08-03 CN CNB00811028XA patent/CN1190112C/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103430633A (en) * | 2011-03-14 | 2013-12-04 | 伊利克塔股份有限公司 | Linear accelerator |
Also Published As
| Publication number | Publication date |
|---|---|
| JP5178978B2 (en) | 2013-04-10 |
| AU6306000A (en) | 2001-03-05 |
| CA2379935A1 (en) | 2001-02-15 |
| US6710557B1 (en) | 2004-03-23 |
| GB2354876B (en) | 2004-06-02 |
| CN1190112C (en) | 2005-02-16 |
| GB2354876A (en) | 2001-04-04 |
| GB9918787D0 (en) | 1999-10-13 |
| EP1203514B1 (en) | 2013-06-19 |
| JP2003506839A (en) | 2003-02-18 |
| EP1203514A1 (en) | 2002-05-08 |
| CA2379935C (en) | 2008-11-04 |
| WO2001011928A1 (en) | 2001-02-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1190112C (en) | Linear accelerator | |
| DE102006062667B4 (en) | Device for the emission of high and / or low energy X-rays | |
| Baldin | Relativistic nuclear physics | |
| US10362666B2 (en) | Compac carbon ion LINAC | |
| JPH11114078A (en) | Charged particle ray irradiating device, charged particle ray rotary irradiating device and charged particle ray irradiating method | |
| CN101142859B (en) | Linear accelerator | |
| Garonna et al. | Cyclinac medical accelerators using pulsed C6+/H2+ ion sources | |
| JP2000284099A (en) | X-ray source and electron beam source for industry using electron beam accelerator | |
| Lynn et al. | Observation of skewed electromagnetic wakefields in an asymmetric structure driven by flat electron bunches | |
| CN1155152A (en) | Charged particle bunch device and operation method thereof | |
| Matsushita et al. | New multipole wiggler/undulator beamline (BL‐16) at the Photon Factory | |
| CN200972460Y (en) | Image and component analyser based on single energy spectrum gamma ray generator | |
| Azhgirey et al. | Measurement of the differential cross section and of the tensor and vector analyzing powers for the fragmentation of 4.5-GeV/c deuterons on beryllium in the reaction involving proton emission at an angle of 80 mrad | |
| Belyaev et al. | Kurchatov Synchrotron Radiation Source status report | |
| Alenitskij et al. | Cyclotron for beam therapy application | |
| Martin | A proton accelerator for medical applications | |
| GB2618844A (en) | Linear accelerator system | |
| Saint et al. | The use of ‘‘mixed’’beams in microprobe imaging | |
| Tanaka | Beam dynamics in a CW microtron for industrial applications | |
| CN116744532A (en) | Current-limiting energy-reducing device for particle beam and application method thereof | |
| Maine | Design and optimisation of new beamlines for iThemba laboratory for accelerator based sciences (iThemba LABS) | |
| Zymierska et al. | Theoretical investigation of defects induced in silicon crystals by high-energy heavy ions | |
| Turner | CAS CERN Accelerator School: Fourth general accelerator physics course | |
| Klem | Proton extraction from a high-energy beam with bent crystals | |
| JPH0513196A (en) | Neutron generating device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term |
Granted publication date: 20050216 |
|
| CX01 | Expiry of patent term |